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keto tuna casserole with zucchini noodles in white casserole dish

Keto Green Chile Tuna Casserole (with zucchini noodles )

  • Author: Lindsay Cotter
  • Total Time: 45
  • Yield: 6 1x


This keto tuna casserole has zucchini noodles and green chiles for a delicious paleo, low-carb, high protein meal. Make this easy spiralizer recipe; it’s just like mom’s tuna noodle casserole, but MUCH healthier!


Units Scale
  • 34 large zucchini (see notes for prep) – Should be close to 5 to 6 cups spiralized noodles
  • 1215 ounces canned tuna (around 2 1/2 – 3 cans) – Drained
  • 1/2 cup real mayo (no additives or sugar added) *add 1/4 cup more if you want extra creamy
  • 4 oz of diced green chiles (no additives added)
  • 2 Tablespoons chopped chives (plus extra for topping)
  • 1/2 teaspoon seasoning salt of choice or natural sea salt with dehydrated garlic or onion added
  • 1 Tablespoon organic mustard (spicy or regular without added sugar)
  • 1/4 teaspoon garlic powder
  • 1/4 teaspoon black pepper
  • 1 Tablespoon olive oil
  • 1/2 cup chopped onion (peeled)
  • 1/2 cup celery (chopped) or green peas
  • 2 Tablespoons coconut flour or tapioca starch (see notes)
  • 1/2 cup almond milk or coconut milk
  • 1/2 teaspoon chili pepper or red pepper flakes
  • Herbs and fresh lemon to garnish (i.e parsley or cilantro)


See notes for tips and whole30 suggestions 

  1. Wash and clean your veggies. Preheat oven to 350 F
  2. Oil a 9x 13 shallow casserole dish. Set aside.
  3. Ribbon cut or spiralize the zucchini into noodles. Press/Squeeze as much excess water out of them as possible. Can use a paper towel. Set aside. (see notes on how to remove excess water from zucchini noodles first)
  4. In another bowl, combine the tuna (drained), mayo, green chiles, chives, mustard, pepper, and garlic powder. Mix thoroughly. Set aside.
  5. Oil a medium skillet. Add the onion, celery and seasoning of choice. Cook for about 6 minutes on medium or until onions begin to brown.
  6. Next add coconut flour and milk to the skillet. Stir together with the celery and onion mix until no longer clumpy. This basically acts as a thickener. It’s okay if it’s not a smooth mixture, just make sure it’s mixable when adding to the zucchini noodles.
  7. Add zucchini noodles to the skillet and toss together. Cover and let the noodles and mix cook together for 1 or 2 minutes on medium heat until zucchini is softened but not thoroughly cooked. Don’t let it get soggy.
  8. NOTE –> Try to press out ALL water from tuna and zucchini before mixing all together. You don’t want the casserole to have too much liquid
  9. Remove skillet from heat and pour contents into a large bowl.
  10. Mix the tuna/green chile mix in the same large bowl (with the zoodles/milk/onion mix). Toss everything together.
  11. Pour mix from the large bowl into the casserole dish. Top with extra seasoning of choice.
  12. Bake for 15 -20 minutes or until edges are brown. If the casserole does not brown after 15 minutes, leave in an extra 5 -10 or until crispy edges.
  13. Broil last minute or so to make crispier edges. Remove from oven.
  14. Garnish with herbs and top and optional sliced lemon.
  15. Serve immediately. Keeps well in sealed container in fridge for up to 1 week. Freezes for up to 6 weeks but will contain extra water once thawed out.


  • Feel free to freeze this dish, but it will have extra water once thawed due to the zucchini. I simply add in more flour or a bit more fresh zucchini.
  • Tapioca starch will be fine if you don’t have coconut flour. Personally, I prefer to use tapioca or arrowroot flour. For Keto friendly ingredients, use sifted coconut flour to avoid clumping. This is your “thickener” for the casserole.
  • ZUCCHINI NOODLE NOTES –> Try to press out ALL water from tuna and zucchini before mixing all together. You don’t want the casserole to have too much liquid. You can also place the zucchini noodles on a baking sheet and “bake” at 250F for 20-30min (depending on the thickness). Thanks to Reader Missy for this tip!

Please comment or email me if you have ANY questions!


  • Prep Time: 20 min
  • Cook Time: 15 -20 min
  • Category: dinner
  • Method: baking
  • Cuisine: American


  • Serving Size: 1
  • Calories: 209
  • Sugar: 3.3g
  • Sodium: 507mg
  • Fat: 16.1g
  • Saturated Fat: 0.2g
  • Carbohydrates: 6.6g
  • Fiber: 2.4g
  • Protein: 10.3g
  • Cholesterol: 22.6mg

Keywords: zucchini casserole, keto tuna casserole, paleo, whole 30, healthy, dairy free